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Plugging USB causes parallel port to hang

0

1

I am developing a parallel port C++ application (on Ubuntu 18.04). Whenever a USB is plugged into the PC while the application is running, it causes one of the following ioctl calls to hang forever. This hang typically happens 2-5 seconds after the USB is inserted, or removed. It is always the ioctl (typically PPCLAIM) that hangs.

Can anyone see something that I am doing wrong in the following example, or is this something I will have to work around?

#include <iostream>
#include <thread>
#include <boost/thread/thread.hpp>
#include <boost/date_time/posix_time/posix_time.hpp>

#include <linux/parport.h>
#include <linux/ppdev.h>
#include <sys/ioctl.h>
#include <sys/stat.h>
#include <fcntl.h>

bool terminate = false;

void native_poll_thread()

 // Create the port fd
 int fd = open("/dev/parport0", O_RDONLY, O_EXCL);

 // Claim and setup the port
 int ioctl_return = 0;
 ioctl_return != ioctl(fd, PPCLAIM);
 ioctl_return != ioctl(fd, PPWDATA, 0);
 ioctl_return != ioctl(fd, PPSETMODE, IEEE1284_MODE_BYTE);
 ioctl_return != ioctl(fd, PPDATADIR, 1);
 int flags = fcntl(fd, F_GETFL, 0);
 ioctl_return != fcntl(fd, F_SETFL, flags 


void using_native()

 std::thread t(&native_poll_thread);

 boost::this_thread::sleep(boost::posix_time::seconds(120));

 terminate = true;
 t.join();



int main(int argc, char *argv[])

 using_native();

Thanks

usb ioctl parallel-port

share|improve this question

edited Mar 13 at 16:05

S90210

asked Mar 13 at 15:55

S90210S90210

11

• 
  
  
  

  
  

  
  
  
  
  
  

  
  
  Is it a parallel-port providing USB thingy? Please edit question with the dmesg output after you put in the USB thingy, whatever it is. My best guess so far is that the USB thingy provides a new /dev/parport0, which renders the old filedescriptor invalid (but that's a wild guess).
  
  – dirkt
  Mar 14 at 8:52
  

  
  
  
  


• 
  
  
  

  
  

  
  
  
  
  
  

  
  
  It's actually a dedicated parallel port PCI-E card
  
  – S90210
  Mar 14 at 13:05
  

  
  
  
  


• 
  
  
  

  
  

  
  
  
  
  
  

  
  
  If it's a PCI-E card, why do you write "USB" = universal serial bus? And I'm serious about the dmesg output - that's the first step to figure out what is going on.
  
  – dirkt
  Mar 14 at 13:53
  

  
  
  
  


• 
  
  
  

  
  

  
  
  
  
  
  

  
  
  Thanks for your suggestion. I meant that when I insert any other USB device (such as a memory stick) into the PC it causes the parallel port application to freeze. I will reword the question and add the dmesg as soon as I get back to my PC.
  
  – S90210
  Mar 14 at 15:26
  

  
  
  
  

add a comment | 

0

1

I am developing a parallel port C++ application (on Ubuntu 18.04). Whenever a USB is plugged into the PC while the application is running, it causes one of the following ioctl calls to hang forever. This hang typically happens 2-5 seconds after the USB is inserted, or removed. It is always the ioctl (typically PPCLAIM) that hangs.

Can anyone see something that I am doing wrong in the following example, or is this something I will have to work around?

#include <iostream>
#include <thread>
#include <boost/thread/thread.hpp>
#include <boost/date_time/posix_time/posix_time.hpp>

#include <linux/parport.h>
#include <linux/ppdev.h>
#include <sys/ioctl.h>
#include <sys/stat.h>
#include <fcntl.h>

bool terminate = false;

void native_poll_thread()

 // Create the port fd
 int fd = open("/dev/parport0", O_RDONLY, O_EXCL);

 // Claim and setup the port
 int ioctl_return = 0;
 ioctl_return != ioctl(fd, PPCLAIM);
 ioctl_return != ioctl(fd, PPWDATA, 0);
 ioctl_return != ioctl(fd, PPSETMODE, IEEE1284_MODE_BYTE);
 ioctl_return != ioctl(fd, PPDATADIR, 1);
 int flags = fcntl(fd, F_GETFL, 0);
 ioctl_return != fcntl(fd, F_SETFL, flags 


void using_native()

 std::thread t(&native_poll_thread);

 boost::this_thread::sleep(boost::posix_time::seconds(120));

 terminate = true;
 t.join();



int main(int argc, char *argv[])

 using_native();

Thanks

usb ioctl parallel-port

share|improve this question

edited Mar 13 at 16:05

S90210

asked Mar 13 at 15:55

S90210S90210

11

• 
  
  
  

  
  

  
  
  
  
  
  

  
  
  Is it a parallel-port providing USB thingy? Please edit question with the dmesg output after you put in the USB thingy, whatever it is. My best guess so far is that the USB thingy provides a new /dev/parport0, which renders the old filedescriptor invalid (but that's a wild guess).
  
  – dirkt
  Mar 14 at 8:52
  

  
  
  
  


• 
  
  
  

  
  

  
  
  
  
  
  

  
  
  It's actually a dedicated parallel port PCI-E card
  
  – S90210
  Mar 14 at 13:05
  

  
  
  
  


• 
  
  
  

  
  

  
  
  
  
  
  

  
  
  If it's a PCI-E card, why do you write "USB" = universal serial bus? And I'm serious about the dmesg output - that's the first step to figure out what is going on.
  
  – dirkt
  Mar 14 at 13:53
  

  
  
  
  


• 
  
  
  

  
  

  
  
  
  
  
  

  
  
  Thanks for your suggestion. I meant that when I insert any other USB device (such as a memory stick) into the PC it causes the parallel port application to freeze. I will reword the question and add the dmesg as soon as I get back to my PC.
  
  – S90210
  Mar 14 at 15:26
  

  
  
  
  

add a comment | 

I am developing a parallel port C++ application (on Ubuntu 18.04). Whenever a USB is plugged into the PC while the application is running, it causes one of the following ioctl calls to hang forever. This hang typically happens 2-5 seconds after the USB is inserted, or removed. It is always the ioctl (typically PPCLAIM) that hangs.

Can anyone see something that I am doing wrong in the following example, or is this something I will have to work around?

#include <iostream>
#include <thread>
#include <boost/thread/thread.hpp>
#include <boost/date_time/posix_time/posix_time.hpp>

#include <linux/parport.h>
#include <linux/ppdev.h>
#include <sys/ioctl.h>
#include <sys/stat.h>
#include <fcntl.h>

bool terminate = false;

void native_poll_thread()

 // Create the port fd
 int fd = open("/dev/parport0", O_RDONLY, O_EXCL);

 // Claim and setup the port
 int ioctl_return = 0;
 ioctl_return != ioctl(fd, PPCLAIM);
 ioctl_return != ioctl(fd, PPWDATA, 0);
 ioctl_return != ioctl(fd, PPSETMODE, IEEE1284_MODE_BYTE);
 ioctl_return != ioctl(fd, PPDATADIR, 1);
 int flags = fcntl(fd, F_GETFL, 0);
 ioctl_return != fcntl(fd, F_SETFL, flags 


void using_native()

 std::thread t(&native_poll_thread);

 boost::this_thread::sleep(boost::posix_time::seconds(120));

 terminate = true;
 t.join();



int main(int argc, char *argv[])

 using_native();

Thanks

usb ioctl parallel-port

share|improve this question

edited Mar 13 at 16:05

S90210

asked Mar 13 at 15:55

S90210S90210

11

#include <iostream>
#include <thread>
#include <boost/thread/thread.hpp>
#include <boost/date_time/posix_time/posix_time.hpp>

#include <linux/parport.h>
#include <linux/ppdev.h>
#include <sys/ioctl.h>
#include <sys/stat.h>
#include <fcntl.h>

bool terminate = false;

void native_poll_thread()

 // Create the port fd
 int fd = open("/dev/parport0", O_RDONLY, O_EXCL);

 // Claim and setup the port
 int ioctl_return = 0;
 ioctl_return != ioctl(fd, PPCLAIM);
 ioctl_return != ioctl(fd, PPWDATA, 0);
 ioctl_return != ioctl(fd, PPSETMODE, IEEE1284_MODE_BYTE);
 ioctl_return != ioctl(fd, PPDATADIR, 1);
 int flags = fcntl(fd, F_GETFL, 0);
 ioctl_return != fcntl(fd, F_SETFL, flags 


void using_native()

 std::thread t(&native_poll_thread);

 boost::this_thread::sleep(boost::posix_time::seconds(120));

 terminate = true;
 t.join();



int main(int argc, char *argv[])

 using_native();

share|improve this question

edited Mar 13 at 16:05

S90210

asked Mar 13 at 15:55

S90210S90210

11

share|improve this question

edited Mar 13 at 16:05

S90210

asked Mar 13 at 15:55

S90210S90210

11

asked Mar 13 at 15:55

S90210S90210

11

asked Mar 13 at 15:55

S90210S90210

11